Question

Students in a large college class took an exam and did poorly. The mean of the scores for the dass was 52 (out of 100), and the standard deviation was 11. The professor felt that the test may have been too difficult and decided to adjust the scores. She multiplied each test score by 1.3 and then added 7 to get the adjusted score. In other words, to obtain the adjusted score y from the original score x, she used the transformation y = 1.3x+7. 1. What is the mean of the adjusted test scores? Do not round your response. 0 2. What is the standard deviation of the adjusted test scores? Do not round your response. 0 6

Answer 1

Given : u = 52 o = 11 a E Cax+b) = a We know that EX) + b sd cax tb) (ع) امى اول Here, y = 1.31 +7 mean = 13 E(X) $ 7 = 1.3 X 52 + 7 mean 74.6 standard deviation 1.3 x + 7 1.3 ox 1.3 X il standard deviation 14.3